The functional vessels of human and animal bodies, such as blood vessels and ducts, occasionally weaken or even rupture. For example, the aortic wall can weaken, resulting in an aneurysm. Upon further exposure to hemodynamic forces, such an aneurysm can rupture.
One surgical intervention for weakened, aneurysmal, or ruptured vessels involves the use of a prosthetic device to provide some or all of the functionality of the original, healthy vessel, and/or preserve any remaining vascular integrity by supporting a length of the existing vessel wall that spans the site of vessel failure. For example, techniques have been developed for repairing aneurysms by intraluminally delivering an endovascular prosthesis to the aneurysm site through the use of a catheter-based delivery system. A prosthesis of this type may be used, for example, to treat aneurysms of the thoracic aorta, abdominal aorta, iliac arteries, or branch vessels, such as the renal arteries. This invention, however, is not so restricted and may be applied to prostheses for placement in any lumen of the human or animal body.
The endovascular grafts typically include a tube of biocompatible pliable material (e.g., expanded polytetrafluoroethylene (ePTFE), polyethylene terephthalate referred to by the brand name Dacron®, or woven polyester) in combination with a graft anchoring component, which operates to hold the tubular graft in its intended position within the aorta. Most commonly, the graft anchoring component is formed of one or more frames or stents that is moveable between a radially inwardly compressed delivery configuration and radially expandable deployed configuration to exert outwardly directing radial pressure against the surrounding blood vessel wall. The stent can be either attached to or incorporated into the body of the tubular graft and/or delivered separately from the graft and subsequently deployed within the graft, or both. Preferably, the graft and stent components are loaded onto a delivery device in a manner that minimizes the load volume and maintains a low delivery profile.